Generational Changes in Repair Stands
This article will discuss the running changes made to older Park Tool repair stands over the course of their existence, for the purpose of obtaining support and replacement parts. Find parts diagrams for these and virtually all other repair stands we have produced in the product documentation library.
PCS-1 and PCS-2 Home Mechanic Repair Stand
The PCS-1 and PCS-2 Home Mechanic Repair Stands have had several changes throughout the years.
Pre-June 1996
The PCS-1 and PCS-2 made before 1996 used a steel top tube that is welded directly to the upright post, as seen in the image below. There is a threaded lever (Part #191-2G) at the top of the top-tube to control rotation of the clamp.
The pre-1996 PCS-1 and PCS-2 stands use the 100-2C clamp. There is no internal thread behind the donut. There is a one-half inch stud extending behind the clamp. There is also a recess machined into the donut of the clamp, sometimes refered to as a “groovy donut”. These clamps will not fit with the current PCS-1 and PCS-4 stands. The 100-9C Adjustable Linkage Clamp will fit this generation of PCS-1 stands.
A few other visually-distinct things of note:
PCS-1 and PCS-2 stands manufactured prior to 1992 feature a moveable jaw with a rounded inner profile and no cable relief. This was a rolling change and the currently-available moveable jaw (part #101-2) is interchangeable with this older style. Note that these two styles also have different jaw covers — see Guide to Replacement Clamp Jaw Covers for more information.
PCS-1 and PCS-2 stands manufactured prior to mid-1994 feature a flat clamp handle rather than a rounded handle. The currently-available handle (part #103-2) is also interchangeable with this older handle style.
June 1996 – December 2001
PCS-1 (June 1996–December 1998)
PCS-1 (December 1998–December 2001)
Beginning in 1996, the PCS-1 and PCS-2 came equipped with a top tube made of a composite material.
The top tube for this generation is part number 939-1. It has no part number embossed behind the handle and will only fit the clamp it was originally equipped with — read on:
The clamp for this generation is called the 100-1CA. There is no extension behind the tapered donut. This clamp is not interchangeable with the 100-1C. There is no other clamp that will fit this stand generation. See the image below.
The 939-1 top tube can be replaced with the newer 939C top tube, which would enable use of the 100-5C Adjustable Linkage Clamp or 100-5D Micro-Adjust Clamp with this generation of PCS-1.
From 1996 to 1998, the PCS-1 was dark grey, with a large knob for adjusting the clamp rotation. From 1998–2001, the PCS-1 was blue, and the knob was replaced with a handle. The two parts are interchangeable, and the stands are otherwise the same.
PCS-1 (June 1996–December 1998) with Knob
PCS-1 (December 1998–December 2001) with Handle
Post-January 2002
PCS-1 (January 2002–January 2004)
PCS-1 (Post-January 2004)
The top tube part number of the final PCS-1 generation is the #939C Universal Top Tube. This model has the number “939” embossed behind the handle, as seen in the image below.
The clamp used in this version of the PCS-1 and PCS-2 Bench Mount is the 100-1C. There are internal threads at the back of the clamp that fit a thread inside the top tube. A cone-shaped sleeve (#149) fits between the clamp and the top tube. The 100-5C Adjustable Linkage Clamp or 100-5D Micro-Adjust Clamp will fit this top tube as well.
The 100-1C clamps produced from January 2002 onward are different than previous clamps. All 100-1C clamps use an internal threading in back of the tapered “donut”. The final generation of clamps has a protrusion that extends the threads, as seen in the image below.
PRS-5 Professional Race Stand
Pre-1996
The first generation of the PRS-5 used a steel top tube, similar to the PRS-3 stand. The clamp used on the pre-1996 PRS-5 was the 100-3C. The lockblock system secures the clamp from rotating, and used a round knob to secure the clamp in the top tube.
June 1996 – December 2001
The PRS-5 stands produced from 1996 to 2001 use the 100-5C clamp. The top tube for these stands is the 939-5C. The upright tube for this generation uses blue oval tubing. The yoke bracket that holds the upright tube is #935. The height adjustment is done with a round knob.
Post-December 2001
The PRS-5 stands manufactured post-2001 use the 939C top tube described above in the PCS-1 section. The clamp used is the 100-5C. This final iteration of the PRS-5 uses a black upright tube. The height adjustment is controlled with a quick-release mechanism. The bracket that holds the upright tube is the #935R Center Yoke. This yoke is not interchangeable with the older PRS-5 stands.
PRS-6, PRS-7, and PRS-8 Repair Stands
Pre-June 1996
On the older PRS-6 and PRS-6W, the locking mechanism is a part #191C positioning knob and shaft, and secures vertically through a threaded fitting at the top of the stand head. The clamp used was the 100-8C, which has a machined recess to accept the 191C swivel foot. The pre-1996 PRS-6 is shown below. The PRS-7 (bench mount) and PRS-8 (wall mount) are of similar design.
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Guide to Replacement Clamp Jaw Covers View Article
Guide to Replacement Clamp Jaw Covers 
